This document provides instructions for students to build an astable circuit on a printed circuit board (PCB). It begins by outlining the learning objectives and assessment criteria. Students are tasked with making a circuit that can warn people of dangers using LEDs, a battery, resistors, capacitors, and transistors. The document provides diagrams of components and their pinouts. It gives a step-by-step process for soldering including safety precautions and checking work. Students are guided through identifying components, placing them correctly on the PCB, and soldering with accuracy. Upon completion, their circuit and soldering skill will be assessed.

1. astable

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think about where
a flashing light is
used

3. Year 7 – astable
W.A.L.T. (we are learning today)
by the end of the lesson you will have learnt;
how to prepare your PCB,
how to identify your components.
W.I.L.F. what I am looking for;
you can give reasons for ‘cleaning’ your PCB,
you are able to reflect on tools and equipment you used
and what safety rules you had to follow.

4. Year 7 – astable
Design brief
Make an astable circuit that can be used to warn people of a dangerous situation.
Specification
It must use a PP3 (9V) battery,
It must be well made,
It must be functional (work),
It must have two LEDs,
It must be as small as possible,
It must be easy to make,
It must be safe,
It must be inexpensive,
It must not drain the battery too quickly,
It must warn people of possible dangers!

5. Year 7 – astable

6. Year 7 – astable
this is the
side you
solder

7. Year 7 – astable
BC
547
BC
547
v
this is the
side for
your
components

8. astable - assessment criteria
Level 3 The tools and equipment you use are always recommended by the
teacher. You demonstrate low level skills to make the astable circuit.
Individual components are not in the correct place. Your soldering is poor.
Mistakes have been corrected by someone else so the circuit works
properly.
Level 4 The tools and equipment you use are sometimes recommended to
you by the teacher. You demonstrate a reasonable level of skill to make
the astable circuit. Individual components are correctly placed but not
lying on the PCB. Your soldering is neat. Mistakes have been corrected
after with help so the circuit works properly.
Level 5 The tools and equipment you use are chosen by you with little help
from the teacher. You demonstrate high level skills to make the astable
circuit. All components are correctly placed and resistors are all the same
way round. All soldering is shiney and cone shaped. Any mistakes have been
corrected independently so the circuit works properly.

9. Year 7 – astable
W.A.L.T. (we are learning today)
by the end of the lesson you will have learnt;
how to identify your components
how to solder correctly.
W.I.L.F. what I am looking for;
you can describe how to solder correctly,
you are able to reflect on tools and equipment you used
and what safety rules you had to follow.

10. astable - assessment criteria
Level 3 The tools and equipment you use are always recommended by the
teacher. You demonstrate low level skills to make the astable circuit.
Individual components are not in the correct place. Your soldering is poor.
Mistakes have been corrected by someone else so the circuit works
properly.
Level 4 The tools and equipment you use are sometimes recommended to
you by the teacher. You demonstrate a reasonable level of skill to make
the astable circuit. Individual components are correctly placed but not
lying on the PCB. Your soldering is neat. Mistakes have been corrected
after with help so the circuit works properly.
Level 5 The tools and equipment you use are chosen by you with little help
from the teacher. You demonstrate high level skills to make the astable
circuit. All components are correctly placed and resistors are all the same
way round. All soldering is shiney and cone shaped. Any mistakes have been
corrected independently so the circuit works properly.

11. Year 7 – astable
this is the
side for
your
components
BC
547
BC
547
v

12. Year 7 – astable
planning for
your
astable
start
clean PCB
drill holes
place battery clip
place/solder
capacitors
finish
place/solder LEDs
place/solder
transistors
check soldering
solder battery clip
place/solder
resistors
check circuit

13. astable - assessment criteria
Level 3 The tools and equipment you use are always recommended by the
teacher. You demonstrate low level skills to make the astable circuit.
Individual components are not in the correct place. Your soldering is poor.
Mistakes have been corrected by someone else so the circuit works
properly.
Level 4 The tools and equipment you use are sometimes recommended to
you by the teacher. You demonstrate a reasonable level of skill to make
the astable circuit. Individual components are correctly placed but not
lying on the PCB. Your soldering is neat. Mistakes have been corrected
after with help so the circuit works properly.
Level 5 The tools and equipment you use are chosen by you with little help
from the teacher. You demonstrate high level skills to make the astable
circuit. All components are correctly placed and resistors are all the same
way round. All soldering is shiney and cone shaped. Any mistakes have been
corrected independently so the circuit works properly.

14. Year 7 – astable
Starter
Using a pencil
line link the
name with the
picture of the
component
with the
description of
what function
it performs.
Component Name Description
LED
(light emitting diode)
This component acts like
a bucket of water that
empty’s out once full.
Then it begins to fill up
until full. It is tubular
shape with legs on either
end.
Resistor
This component acts like
an electronic switch
which only turns on
when a certain amount of
current flows to it. This
component has three
legs, is curved on one
side with writing on the
other.
Capacitor
This component lights up
and only allows current
to flow one way around a
circuit.
It is shaped like a dome
with a single flat side and
one leg longer than the
other.
Transistor
This component controls
the amount of current
flowing around a circuit.
This helps to protect
other components from
burning out. They are
thin with coloured bands
around them and tubular
shaped.

15. Year 7 – astable
W.A.L.T. (we are learning today)
by the end of the lesson you will have learnt;
how to identify your components
what safety precautions I need to take when soldering
how to solder accurately and correctly
W.I.L.F. what I am looking for;
You are able to link the name with a picture and description
correctly
what safety rules you had to follow when soldering
you are able to solder your components to your PCB so they
function as intended.

16. Year 7 – astable
What the video.
While watching the video note down some safety rules I am following
or should be following.
What might I be wearing that you can’t see because I am behind the
camera?

17. Year 7 – astable
Using the safety rules you have come up will start to solder your
components to your board.
Make sure your components are in the right places and the right way
around.
Use my example, the flow charts, or the help sheets provided or
even another student.

18. Year 7 – astable
this is the
side you
solder

19. Year 7 – astable
BC
547
BC
547
v
this is the
side for
your
components

20. Year 7 – astable
planning for
your
astable
start
clean PCB
drill holes
place battery clip
place/solder
capacitors
finish
place/solder LEDs
place/solder
transistors
check soldering
solder battery clip
place/solder
resistors
check circuit

21. astable - assessment criteria
Level 3 The tools and equipment you use are always recommended by the
teacher. You demonstrate low level skills to make the astable circuit.
Individual components are not in the correct place. Your soldering is poor.
Mistakes have been corrected by someone else so the circuit works
properly.
Level 4 The tools and equipment you use are sometimes recommended to
you by the teacher. You demonstrate a reasonable level of skill to make
the astable circuit. Individual components are correctly placed but not
lying on the PCB. Your soldering is neat. Mistakes have been corrected
after with help so the circuit works properly.
Level 5 The tools and equipment you use are chosen by you with little help
from the teacher. You demonstrate high level skills to make the astable
circuit. All components are correctly placed and resistors are all the same
way round. All soldering is shiney and cone shaped. Any mistakes have been
corrected independently so the circuit works properly.

22. Year 7 – astable
W.A.L.T. (we are learning today)
by the end of the lesson you will have learnt;
how to identify your components
what safety precautions I need to take when soldering
how to solder accurately and correctly
W.I.L.F. what I am looking for;
You are able to link the name with a picture and description
correctly
what safety rules you had to follow when soldering
you are able to solder your components to your PCB so they
function as intended.

23. Year 7 – astable
Plenary
Come up with one rule when soldering
State three things you need to do when soldering
Describe an accurate and correct solder joint ( what should it look
like?